This application claims priority to Japanese Patent Application No. HEI 11-134301, which was filed on May 14, 1999 and is hereby incorporated by reference.
1. Field of the Invention
The invention relates to a vehicle lamp, and more specifically to a structure for a lighting unit that utilizes a discharge lamp such as a metal halide discharge lamp, etc. as a light source for lighting a headlamp.
2. Description of Related Art
A discharge lamp 91, as shown in FIG. 3, is typically used as a light source for a headlamp and includes a resin base 92 located at a predetermined position on the reflector 81 of the headlamp 80. A flange section 92a is provided at the resin base 92, so as to position the base 92 with respect to the reflector 81.
A metal burner band 91b is mounted adjacent an outer bulb 91a of the discharge lamp 91 and is welded to the resin base 92. The position of the discharge lamp 91 and the resin base 92 is determined with reference to the flange section 92a. A discharge chamber 91c can be given a predetermined position by fitting the lamp 91 to the reflector 81. Ceramic plate 94 is provided to protect the resin base 92 from high temperature when the discharge lamp 91 is lit.
When the discharge lamp 91 is started, approximately 25,000V is applied to the lamp. Electrical wiring is provided to supply the high voltage to the resin base 92. The high voltage wiring extends to the outside of the headlamp 80 and should therefore be housed.
As shown in FIG. 4, for example, Japanese Patent Publication Laid-open No. HEI. 8-315624, a driver case 93 is formed integrally with the resin base 92, and houses a starter circuit and a high voltage transformer (not shown) within the driver case 93 to create a lighting unit 90. A headlamp 90 can then be implemented with a 12V supply.
With the above lighting unit 90, the structure for mounting to the reflector 81 is the same as with the structure for mounting to the resin base 92 of lighting unit 80. When the reflector 81 is mounted as shown in FIG. 3, electrical leaks may occur between the electrodes and the metal plated reflector 81 or between the electrodes and a hood 82 mounted to the reflector 81.
In addition, when either one of the discharge lamp 91 or the drive case 93 is defective, the whole lighting unit 90 has to be replaced because the driver case 93 is formed integrally with the resin base 92. This design does not effectively utilize resources. It is also necessary to separate the driver case 93 and the discharge lamp 91 when the unit is scrapped, which is a difficult operation and increases overall costs.
Additional features and advantages of the invention will be set forth in the description that follows, and in part, will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and achieved by the structure particularly out in the written description and claims hereof as well as the appended drawings.
In order to resolve the aforementioned problems, an embodiment of the invention provides a vehicle discharge lighting unit with an integrally formed discharge lamp, starter circuit, and high voltage transformer which includes a bulb mounting slot, a mounting flange, and a burner band mounting section. The bulb mounting slot is provided at a resin base mounted at a discharge lamp bulb section, whose slot diameter fits with an outer bulb of the discharge lamp bulb section and has a broad input-side slot width. The mounting flange supports the resin base on a reflector. A driver case which houses the starter circuit and high voltage transformer can also be mounted to the reflector. The burner band mounting section extends along a discharge chamber direction and project within the reflector.
To achieve this and other advantages, and in accordance with the purpose of the invention, as embodied and broadly described the invention provides a vehicle lighting unit including a lamp, starter circuit, and transformer, said unit including a base having a bulb mounting slot located at a discharge lamp bulb section, a driver case which houses the starter circuit and the transformer, a reflector, a mounting flange for supporting the base and mounting the driver case to the reflector and a burner band mounting section extending towards the lamp and projecting within the reflector.
In accordance with another aspect of the invention, a vehicle lighting unit includes a base having a mounting slot, a lamp positionably located in the mounting slot on the base, a driver unit including a transformer and a starter circuit, a driver case for housing the driver unit, the driver case including means for mounting the base at a predetermined position relative to the driver case and for being removably attached to the base.
In accordance with yet another aspect of the invention, a method for assembling a vehicle lighting unit that includes the steps of positioning a lamp in a mounting slot on a base, attaching the base in a driver case, and connecting the driver case to a reflector. The method is for assembling a lamp that includes a base having a mounting slot, a lamp positionably located in the mounting slot on the base, a driver unit, and a driver case configured to house the driver unit and mount the base at a predetermined position, the base being removably attached to the driver case.
Further, in the invention, the driver case can be formed so as to be separable into a front case and a rear case along a direction of the resin base that is substantially orthogonal to the axis of the discharge lamp. The resin base supporting the discharge lamp also can be formed integrally with the front case so that changing of the discharge lamp is possible.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.